slartgp.f3

!>
!> SLARTGP generates a plane rotation so that
!>
!>    [  CS  SN  ]  .  [ F ]  =  [ R ]   where CS**2 + SN**2 = 1.
!>    [ -SN  CS  ]     [ G ]     [ 0 ]
!>
!> This is a slower, more accurate version of the Level 1 BLAS routine SROTG,
!> with the following other differences:
!>    F and G are unchanged on return.
!>    If G=0, then CS=(+/-)1 and SN=0.
!>    If F=0 and (G .ne. 0), then CS=0 and SN=(+/-)1.
!>
!> The sign is chosen so that R >= 0.
!> 

F

!>          F is REAL
!>          The first component of vector to be rotated.
!> 

G

!>          G is REAL
!>          The second component of vector to be rotated.
!> 

CS

!>          CS is REAL
!>          The cosine of the rotation.
!> 

SN

!>          SN is REAL
!>          The sine of the rotation.
!> 

R

!>          R is REAL
!>          The nonzero component of the rotated vector.
!>
!>  This version has a few statements commented out for thread safety
!>  (machine parameters are computed on each entry). 10 feb 03, SJH.
!> 

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